Some people say that sugar in your gas tank will not ruin your engine. I can tell you first had it will ruin your engine.
Here is the story on how I found out there was sugar in my gas tank. One day I decided to tank my 64 Nova for a cruise like I normally do. I was driving the car on the freeway for a little bit I guess long enough to get to the point where the sugar was cooking inside my cylinder heads, intake manifold and even carburetor. When sugar cooks and boils its gets very sticky right. The sugar inside my carb was not allowing the carburetor to function properly and was keeping the throttle blades open not allowing the car to slow down.
I was driving the car on the freeway and I was approaching traffic so I gradually step on the brakes to slow down and successfully slowed down, and as I took my foot off the brake and rested my foot on the floor the car again began to accelerate as I was approaching the stopped cars. That was pretty scary. I stepped on the brakes again to get the car to slow down and again I took my foot off the gas and again the car continued to speed up, this time I thought maybe my gas pedal was sticking so I tried to pull it out and it would not work.
In fact the accelerating actually got worse and I picked up more speed and more rpms. Luckily, I was at my off ramp. In order to get the car home I had to use two feet to drive the car home, one on the gas and one on the brake, and pretty much just rode the brakes all the way home. It was very scary and don't let anybody tell you that sugar will not ruin a engine because it will. I know first hand and to rebuild my engine a shop wanted about $2200.
Take a look at these pictures.
The fist thing I did was take off the fuel filter before the carb and found this. The sugar formed a big sugar crystal inside my filter with a hole just big enough to let gas and sugar flow together. I decided to taste a little bit and sure enough it was sugar!
When I saw this I realized there was a major problem and decided to look down my fuel filler neck.
Guess what more freaking sugar!
Now inside the gas tank. Looks like snow, but its about a whole bag of sugar.
Now to what the inside of the engine will look like. This is inside the intake manifold. The carb bolts right on top. Thats a sugar coating forming going all the way down to the cylinder heads.
Inside the cylinder head looked like this:
And of course the top of my pistons:
And heres the build up inside the floats on my carburetor.
Its hard to see in this pic but theres was actually a white coating around the black butterflies causing the carb not close fully allowing the carb to continue to give the car gas and the car was basically driving around at 2500 rpms all on its own.
In my experience sugar will ruin your engine. People say the fuel filters will stop it. Not mine, I had 2 fuel filters, one by the gas tank and one before the carb. If your lucky your fuel injectors will get clogged first but not likely, sugar will makes it way through and start to boil and stick to the insider of your engine resulting in a slow death and no car!